Ram-actuated telescoping hollow arm



May 20, 1969 R. A. SAMPO ET L RAM-ACTUATED TELESCOPING HOLLOW AYRM Filed Dec. 9, 1966 //v VET/V7025- ROBERT A. 5.4 MP0, Toxvy A. 54 MP0 BY THE/E ATTORNEYS HARE/5, K/EcH, Russaz. &A =v2/v United States Patent 3,445,015 RAM-ACTUATED TELESCOPING HOLLOW ARM Robert A. Sampo, 4842 Ocana Ave., Lakewood, Calif.

90713, and Tony A. Sampo, 4663 Deerboyar, Lakewood, Calif. 90712 Filed Dec. 9, 1966, Ser. No. 600,479 Int. Cl. E02f 3/ 74 US. Cl. 214--138 5 Claims ABSTRACT OF THE DISCLOSURE A telescoping backhoe dipper stick comprising telescopically interconnected inner and outer tubular members containing a ram for lengthening and shortening the dipper stick. The inner tubular member is connected to the backhoe boom while the backhoe bucket is connected to the outer tubular member. Thus, the inner tubular member is remote from the bucket to minimize its exposure to dirt, thereby minimizing the possibility of dirt entering the sliding connection between the inner and outer members.

Background of invention The present invention relates in general to a telescoping hollow arm containing a ram for extending and contracting the arm to extend and retract an implement carried thereby.

The invention is particularly useful as a backhoe dipper stick, extension and contraction of the dipper stick by the ram therein serving to extend and retract the bucket of the backhoe relative to the boom thereof. Consequently, the invention will be considered in such an environment herein for convenience in disclosing same, with the under- Standing that the invention may be used for other purposes.

Conventionally, a backhoe dipper stick of the foregoing type includes an outer tubular member pivotally connected to the boom of the backhoe and an inner tubular member telescoped into the outer tubular member and having the bucket of the backhoe pivotally mounted thereon.

With the foregoing conventional construction, the inner tubular member is almost constantly exposed to the dirt being dug by the bucket since it is immediately adjacent thereto. Whenever the dipper stick is contracted, dirt is carried into the sliding connection between the inner and outer tubular members. This results in a great deal of Wear in the area of the telescoping connection between the two tubular members. Also, with this conventional construction, it is possible for dirt to enter the interior of the hollow dipper stick around the ram therein, which is obviously undesirable.

Objects of invention A primary object of the invention is to eliminate the foregoing disadvantages of conventional backhoe dipper sticks by minimizing exposure of the inner tubular member to dirt being dug by the backhoe bucket and by making it substantially impossible for dirt to enter the interior of the hollow dipper stick.

More particularly, an important object of the invention is to make the inner tubular member of the dipper stick the member which is pivotally connected to the boom, and to make the outer tubular member the member on which the bucket is pivotally mounted. With this construction, the inner tubular member is remote from the bucket to minimize its exposure to the dirt being dug by the bucket. Consequently, the amount of dirt which can enter the sliding connection between the inner and outer 3,445,015 Patented May 20, 1969 tubular members is minimized to minimize wear, which is an important feature of the invention.

Another important object of the invention is to provide a telescoping hollow dipper stick which is materially simpler and lighter in weight than prior dipper sticks, while retaining at least equal strength.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the digging art, and any other arts in which the invention may be used, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawing.

Description of drawing In the drawing:

FIG. 1 is a side elevational view on a reduced scale of a backhoe boom assembly which utilizes as its dipper stick a ram-actuated telescoping hollow arm of the invention;

FIG. 2 is a longitudinal sectional view of the dipper stick in its contracted condition;

FIG. 3 is a view similar to FIG. 2, but showing the dipper stick in a partially extended condition; and

FIG. 4 is an enlarged transverse sectional view taken as indicated by the arrowed line 44 of FIG. 3.

Description of preferred embodiment of invention Referring initially to FIG. 1 of the drawing, illustrated therein is a backhoe boom assembly 10 which includes a boom 12 and a dipper stick 14 pivotally connected to the outer end of the boom 12 by a pivot means 16. As is conventional, the dipper stick 14 is pivoted relative to the boom 12 by a ram 18 pivotally connected to the boom at 20 and to the dipper stick at 22.

The dipper stick 14 consists of a telescoping hollow arm comprising an inner tubular member 24 and an outer tubular member 26 telescoped over the inner tubular member. As shown in FIG. 4, the inner and outer tubular members 24 and 26 are provided with a noncircular cross section to permit relative longitudinal sliding movement of these members while preventing relative rotation thereof. Preferably, the inner and outer tubular members 24 and 26 are rectangular with the long axes of the rectangles in the plane of the boom assembly 10 for maximum beam strength.

The inner end of the inner tubular member 24 is pro vided thereon with a bracket structure 28 which connects the dipper stick 14 to the boom 12 through the pivot means 16, and to which the ram 18 is connected by the pivot 22. The bracket structure 28 includes closure means 30 for at least substantially closing the inner end of the inner tubular member 24 to exclude dirt therefrom.

The outer end of the outer tubular member 26 is completely closed by a closure means 32 welded, or otherwise secured, thereto. The closure means 32 precludes any possibility of dirt entering the interior of the hollow dipper stick 24, which is an important feature. The closure means 30 prevents, or substantially prevents, the entry of dirt from the inner end of the dipper stick 14.

Within the hollow dipper stick 14, and extending longitudinally thereof, is a ram 34 for extending and contnacting the dipper stick. One end of the ram 34 is pivotally connected to the inner tubular member 24 at 36, and the other end of the ram is pivotally connected to the outer tubular member 26 at 38. Lines 40 leading to opposite ends of the ram 34 preferably pass out of the interior of the dipper stick 14 through the closure means 30, which can be provided with suitable seals around the lines 40 to substantially completely eliminate any 3 possibility of dirt entering the dipper stick 14 from the inner end thereof.

The outer end of the dipper stick 14 carries a backhoe bucket 42 which is pivotally connected to the outer tubular member 26 by a pivot means 44 parallel to the pivot means 16. The bucket 42 is controlled by a ram 46 pivotally connected at one end to a bracket structure 48 welded, or otherwise secured, to the exterior of the outer tubular member 26 adjacent the inner end thereof. The other end of the ram 46 is pivotally connected to linkage means 50 and 52 which are respectively pivotally connect-ed to the outer end of the outer tubular member 26 and to the bucket 42. As will be apparent, the ram 46 controls the angular position of the bucket 42 relative to the dipper stick 14 in a conventional manner.

With the foregoing construction for the dipper stick 14, the outer tubular member 26 constitutes the outer end of the dipper stick and is the member which is most exposed to the dirt being dug by the bucket 42. In other words, the inner tubular member 24, on which dirt must fall to enter the sliding connection between the inner and outer tubular members 24 and 26, is remote from the bucket 42 so that its exposure to dirt is greatly minimized. Consequently, relatively little dirt enters the sliding connection between the inner and outer tubular members 24 and 26, as compared to prior dipper sticks, with the result that wear is minimized.

Also, since the outer end of the outer tubular member 26 is completely closed by the closure means 32, and since the ram 46 for pivoting the bucket 42 is mounted entirely on the outer tubular member 26, there is virtually no possibility of dirt entering the interior of the dipper stick 14. It is important to note that since the outer tubular member 26 is the one which carries the ram 46, it is unnecessary to slot either of the telescoping members to accommodate this ram, thereby eliminating a possible point of dirt entry. The fact that the inner end of the inner tubular member 24 is closed, or substantially closed, by the closure means 30 also eliminates or minimizes the possibility of entry of dirt at this point.

Although an exemplary embodiment of the present invention has been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims which follow.

We claim as our invention:

1. In an articulated digging assembly, the combination of:-

(a) a vertically swingable boom;

(b) a telescoping hollow arm carried by said boom;

(c) said hollow arm including an inner tubular member having an inner end pivotally connected to the outer end of said boom;

(d) said hollow arm including an outer, circumferentially continuous, tubular member telescoped over said inner tubular member and having an outer end;

(e) a bucket pivotally connected to the outer end of said outer tubular member;

(f) a ram within and extending longitudinally of said hollow arm and having its respective ends connected to said inner and outer tubular members; (g) means closing the outer end of said outer tubular member; and (h) means secured to the outside of :said outer tubular member for pivotally moving said bucket. 2. An articulated digging assembly as defined in claim 1 including means substantially closing the inner end of said inner tubular member.

3. An articulated digging assembly according to claim 1:

(a) said last-named means comprises another ram externally of and generally parallel to said outer tubular member;

('b) means pivotally connecting one end of said other ram to said outer tubular member adjacent the inner end thereof; and

(0) means pivotally connecting the other end of said other ram to said bucket.

4. In a telescoping hollow arm for connecting an implement to a support, the combination of:

(a) an inner tubular member having an inner end;

(b) an outer tubular member telscoped over said inner tubular member and having an outer end;

(c) a ram within and extending logitudinally of said hollow arm and having its respective ends connected to said inner and outer tubular members;

(d) means closing said outer end of said outer tubular member;

(e) means at said inner end of said inner tubular member for mounting said telescoping hollow arm on the support;

(f) means at said outer end of said outer tubular member pivotally mounting the implement on said telescoping hollow arm;

(g) another ram externally of and generally parallel to said outer tubular member;

(h) means pivotally connecting one end of said other ram to said outer tubular member adjacent said inner end thereof; and

(i) means for pivotally connecting the other end of said other ram to the implement.

5. A telescoping hollow arm as set forth in claim 4 including means substantially closing said inner end of said inner tubular member.

References Cited UNITED STATES PATENTS 2,411,498 11/1946 Billings 214138 2,746,612 5/1956 Wirz 212-55 X 2,791,341 5/1957 Michaels et al. 214141 3,140,785 7/1964 Pilch 214138 3,184,085 5/1965 Randall et al. 214l38 3,292,800 12/1966 lleremiasen 214138 HUGO O. SCHULZ, Primary Examiner.

US. Cl. X.R. 214141 

